In the field of power operated loading and unloading equipment or apparatus for use on vehicles such as a truck body or a semi-trailer body, there are many different types of loaders which mount on the rear portion of the vehicle body for use in connection with a doorway opening at the rear of the body. There has also been a number of different types of power operated loaders designed for use in connection with a doorway within a side wall of a truck or trailer body, for example, as disclosed in U.S. Pat. Nos. 3,263,835, 3,368,704, 3,710,962 and 4,214,849.
It is sometimes desirable to provide a full size truck or trailer body with retractable loading apparatus for a doorway within a side wall of the body and for the loading apparatus to be carried by the truck or trailer body without adding to the overall width of the body. For example, many box-like truck and trailer bodies have an overall width of eight feet which is the maximum width permitted by many states. Such bodies are also frequently constructed with U-shaped channel sections which eliminate the need for a main support frame extending under the bed or floor deck of the body. With such frameless bodies, it is important that the unitary construction of the body be maintained and without any modification which reduces the strength of the body. As apparent after reviewing the above-mentioned patents, none of the different loading apparatus disclosed in these patents is adapted for use in connection with a frameless trailer body having a maximum overall width.